This paper investigated the urban heat island effect (UHIE) in the Spanish Mediterranean over the 1950–2013 period. The scientists found most of the temperature rise of urban stations occurred in the minimum temperatures, an indication of the UHIE. Satellite-based AVHRR infrared imagery was used to study the urbanization effects from 2001 to 2014. The abstract says “The results obtained have shown both the nature of the [UHIE] phenomenon and its significant magnitude. This magnitude could account for between 70 and 80% of the recorded warming trend in Western Mediterranean cities. Therefore, failure to take this process into account might seriously bias any analysis of regional thermal evolution, the main aim of this study and an aim that equally affects the hypothesis of global climate change.”

This study investigates the urban heat island effect (UHIE) on a national scale. It compared the national energy consumption (which is converted to heat) to average national temperatures for the United Kingdom and Japan. Strong correlations are found between energy consumption and temperatures above or below global background levels. In the U.K. for example, temperatures correlate to energy consumption with r2 = 0.89, which is very much greater than the correlation to the CMIP5 climate models used in the last IPCC report of only r2 = 0.10. The abstract says “It is clear that the fluctuation in [temperature] are better explained by energy consumption than by present climate models.

A new study by Watts et al shows that bad siting of temperature stations has resulted in NOAA overestimating US warming trends by 59% since 1979. The study identified a subset of 410 US Historical Climate Network stations, that have not been moved, had equipment changes, or changes in time of observations, and thus require no “adjustments” to their temperature record. These stations were classified as well sited and poorly sited, based on a WMO approved metric Leroy (2010). The news release states, "We believe the NOAA/NCDC homogenization adjustment causes well sited stations to be adjusted upwards to match the trends of poorly sited stations".

Dr. Roy Spencer describes a new technique for for estimating the average amount of urban heat island (UHI) warming accompanying an increase in population density. The most rapid rate of warming with population increase is at the lowest population densities, while some warming continues with population increases even for densely populated cities. A population density of only 100 persons per sq. km exhibits average warming of about 1.1 deg. C compared to a nearby unpopulated temperature monitoring location.

Climate scientists are supposed to correct the temperature record to eliminate the urban heat island effect. But they do just the opposite. They adjust rural stations to increase their warming trends. The urban warming "adjustment protocol appears to accent to a warming effect rather than eliminate it."